1. Field of the Invention
This invention relates in general to vanes for rotary vane pumps, and in particular to a thermoplastic fiber impregnated rotor vane and method for making the rotor vane.
2. Description of the Prior Art
Rotor vanes for rotary vane pumps, which include compressor pumps, have had various constructions formed by various methods to improve the wear resistance of the vanes. Rotor vanes have been constructed of single materials into shapes which radially extend from rotors of rotary vane pumps to seal against the oval or elliptical shaped walls of pressure chambers. Rubbing of the tips of the rotor vanes along the walls of pressure chambers wears the tips of the vanes, eventually leading to failure of the rotary vane pumps.
There have been numerous attempts to successfully construct rotor vanes of composite materials. An earlier type of rotor vane had a vane tip constructed of fibrous materials impregnated with resinous compounds. Other vanes have been formed by bonding together several layers of woven fabric which are first impregnated with the plastic materials. The layers of woven fabric in this later type of vane construction alternate between layers of plastic material which bond the fabric layers together. The alternating layers of plastic materials and woven fabric results in nonuniform mechanical properties across the transverse thickness of vanes.
Several problems have occurred with prior art rotor vanes. Typically, rotor vane tips formed of fibrous materials impregnated with resinous compounds tend to wear after extended periods of use, causing pump failures. The rotor vanes formed of layers of woven fabric alternating between layers of plastic materials also wear after extended periods of use, and often the layers delaminate due to the varying mechanical properties across the transverse thickness of these later type of vanes.